The subject matter disclosed herein relates to communication systems, and more particularly, to systems and methods of conducting handoffs based on voice quality of a communication.
A communication system may include communication devices capable of transmitting and receiving human speech. For example, a user may speak into a first communication device, and the speech waveform may be compressed and digitized and then transmitted to a second communication device. The compressed digital signal may be decompressed to reconstruct an approximation of the original speech waveform. The compression and decompression of speech signals in a communication system may involve voice encoders, commonly referred to as “vocoders.”
Communication devices may be connected within a network through different communication routes. Each communication route connecting a device within the network may include a link between the device and a vocoder. The vocoder may be linked to a network node, which may be connected through its own subnetwork within the communication network. A communication network may have multiple communication routes, as the network may include multiple subnetworks, network nodes, and vocoders. The particular communication route of a communication device may depend on the signal strength between the device and the node. As signal strength may change during a communication, the link between a device and a node may sometimes be switched to maintain an acceptable signal strength. For example, a connection between a communication device and a first network node may be switched to enable a communication between the device and a second network node for increased signal strength. Such a switch in communication between device and network node may be referred to as a “handoff.”
As communication systems evolve, other parameters in addition to signal strength may be used in conducting handoffs in a communication network. While signal strength may be used as a metric for conducting a handoff between network nodes connected to a fixed circuit-switched landline, signal strength alone may be an inadequate metric for conducting handoffs in a multimedia communication network using a multi-hop packet-switched system. A multimedia network system may include different types of wireless services (e.g., cellular services and VoIP services) which transmit packets over different links (e.g., fixed links or radio frequency links) having different frequencies and different degradation characteristics. Furthermore, different communication technologies may use vocoders having different architectures or incompatible bit streams, which may also affect speech transmission. Thus, using a metric more suitable for a multimedia communication network may improve communication quality.